AB0117 IMMUNE CELL IMBALANCES IN PLACENTAS OF SYSTEMIC LUPUS ERYTHEMATOSUS AND SJÖGREN’S SYNDROME PATIENTS
Authors: J. J. Fierro, G. M. Verstappen, J. R. Prins, J. Westra, H. Bootsma, K. de Leeuw
Journal: Annals of the Rheumatic Diseases (2022)

Background Systemic lupus erythematosus (SLE) and primary Sjögren’s syndrome (pSS) are associated with adverse pregnancy outcomes (APOs) [1,2]. During pregnancy, maternal immune activation is related to a higher risk of hypertension, preeclampsia, preterm labor, and fetal growth restriction in SLE patients [1]. Furthermore, these patients have an increased risk of neonatal lupus due to the transplacental passage of maternal anti-RO/SSA antibodies to the fetus [3]. Nevertheless, there is no compelling evidence about the type of immune cell imbalances in the placenta in patients with SLE and pSS. Objectives Identify immunologic imbalances, focusing on interferon (IFN) and immune cell subtypes in placenta tissue of patients with SLE or pSS. Methods Retrospective analysis of immune cell composition of paraffin-embedded placental tissue from 6 SLE, 4 pSS, and 12 healthy women was conducted. For each case, one full-thickness sample of normal-appearing parenchyma from the central two-thirds of the placental disc was taken. APOs history and pregnancy outcomes were recorded. Placenta immunohistochemistry stainings were done for myxovirus resistance protein A (MxA, an interferon induced protein), CD3, CD20, CD45 and CD68. Statistical analysis was performed with a non-parametric T-test. Results A significantly higher MxA expression in the placenta of SLE and pSS patients compared to healthy controls was observed (Figure 1A). SLE patients had an increased MxA expression in decidua and villi compared with controls, while in pSS patients this increase was found in amnion and villi. The count of T cells, B cells, total leukocytes, and macrophages in the decidua tissue were comparable between groups (Figure 1B). However, a significantly higher macrophage per total number of cells index was observed in SLE and pSS patients compared to healthy controls (Figure 1C). Only two patients had no APOs. Therefore, no analysis was performed comparing patients with or without APO. Conclusion A higher macrophage count and an increased IFN expression were identified in the placentas of SLE and pSS patients. These findings suggest a proinflammatory placental environment that could be related to APOs presentation in patients with SLE and pSS. However, to establish the relation with APOs further studies are needed including more patients especially without APOs. References [1]Bundhun PK, Soogund MZ, Huang F. Impact of systemic lupus erythematosus on maternal and fetal outcomes following pregnancy: A meta-analysis of studies published between years 2001-2016. J Autoimmun. 2017;79:17–27. [2]Elliott B, Spence AR, Czuzoj-Shulman N, Abenhaim HA. Effect of Sjogren’s syndrome on maternal and neonatal outcomes of pregnancy. J Perinat Med. 2019;47(6):637–42. [3]Zuppa AA, Riccardi R, Frezza S, Gallini F, Luciano RM, Alighieri G, et al. Neonatal lupus: Follow-up in infants with anti-SSA/Ro antibodies and review of the literature. Autoimmun Rev. 2017;16(4):427–32. Disclosure of Interests None declared